diff options
Diffstat (limited to 'src/util/crypto_contract.c')
| -rw-r--r-- | src/util/crypto_contract.c | 209 |
1 files changed, 196 insertions, 13 deletions
diff --git a/src/util/crypto_contract.c b/src/util/crypto_contract.c index 30fdec789..fe6b1e6af 100644 --- a/src/util/crypto_contract.c +++ b/src/util/crypto_contract.c @@ -34,7 +34,12 @@ enum ContractFormats * can merge it into a reserve/account to accept the contract and * obtain the payment. */ - TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER = 0 + TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER = 0, + + /** + * The encrypted contract represents a payment request. + */ + TALER_EXCHANGE_CONTRACT_PAYMENT_REQUEST = 1 }; @@ -192,7 +197,7 @@ contract_decrypt (const void *key, /** * Header for encrypted contracts. */ -struct ContractHeader +struct ContractHeaderP { /** * Type of the contract, in NBO. @@ -203,15 +208,23 @@ struct ContractHeader * Length of the encrypted contract, in NBO. */ uint32_t clen; +}; + +/** + * Header for encrypted contracts. + */ +struct ContractHeaderMergeP +{ /** - * Included key material, depending on @e ctype. + * Generic header. */ - union - { - struct TALER_PurseMergePrivateKeyP merge_priv; - } keys; + struct ContractHeaderP header; + /** + * Private key with the merge capability. + */ + struct TALER_PurseMergePrivateKeyP merge_priv; }; @@ -234,7 +247,7 @@ TALER_CRYPTO_contract_encrypt_for_merge ( char *cstr; size_t clen; void *xbuf; - struct ContractHeader *hdr; + struct ContractHeaderMergeP *hdr; struct NonceP nonce; uLongf cbuf_size; int ret; @@ -255,9 +268,9 @@ TALER_CRYPTO_contract_encrypt_for_merge ( GNUNET_assert (Z_OK == ret); free (cstr); hdr = GNUNET_malloc (sizeof (*hdr) + cbuf_size); - hdr->ctype = htonl (TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER); - hdr->clen = htonl ((uint32_t) clen); - hdr->keys.merge_priv = *merge_priv; + hdr->header.ctype = htonl (TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER); + hdr->header.clen = htonl ((uint32_t) clen); + hdr->merge_priv = *merge_priv; memcpy (&hdr[1], xbuf, cbuf_size); @@ -288,7 +301,7 @@ TALER_CRYPTO_contract_decrypt_for_merge ( struct GNUNET_HashCode key; void *xhdr; size_t hdr_size; - const struct ContractHeader *hdr; + const struct ContractHeaderMergeP *hdr; char *cstr; uLongf clen; json_error_t json_error; @@ -321,6 +334,177 @@ TALER_CRYPTO_contract_decrypt_for_merge ( return NULL; } hdr = xhdr; + if (TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER != ntohl (hdr->header.ctype)) + { + GNUNET_break_op (0); + GNUNET_free (xhdr); + return NULL; + } + clen = ntohl (hdr->header.clen); + if (clen >= GNUNET_MAX_MALLOC_CHECKED) + { + GNUNET_break_op (0); + GNUNET_free (xhdr); + return NULL; + } + cstr = GNUNET_malloc (clen + 1); + if (Z_OK != + uncompress ((Bytef *) cstr, + &clen, + (const Bytef *) &hdr[1], + hdr_size - sizeof (*hdr))) + { + GNUNET_break_op (0); + GNUNET_free (cstr); + GNUNET_free (xhdr); + return NULL; + } + *merge_priv = hdr->merge_priv; + GNUNET_free (xhdr); + ret = json_loadb ((char *) cstr, + clen, + JSON_DECODE_ANY, + &json_error); + if (NULL == ret) + { + GNUNET_break_op (0); + GNUNET_free (cstr); + return NULL; + } + GNUNET_free (cstr); + return ret; +} + + +/** + * Salt we use when encrypting contracts for merge. + */ +#define DEPOSIT_SALT "p2p-deposit-contract" + + +void +TALER_CRYPTO_contract_encrypt_for_deposit ( + const struct TALER_PurseContractPublicKeyP *purse_pub, + const struct TALER_ContractDiffiePrivateP *contract_priv, + const json_t *contract_terms, + void **econtract, + size_t *econtract_size) +{ + struct GNUNET_HashCode key; + char *cstr; + size_t clen; + void *xbuf; + struct ContractHeaderP *hdr; + struct NonceP nonce; + uLongf cbuf_size; + int ret; + void *xecontract; + size_t xecontract_size; + + GNUNET_assert (GNUNET_OK == + GNUNET_CRYPTO_ecdh_eddsa (&contract_priv->ecdhe_priv, + &purse_pub->eddsa_pub, + &key)); + cstr = json_dumps (contract_terms, + JSON_COMPACT | JSON_SORT_KEYS); + clen = strlen (cstr); + cbuf_size = compressBound (clen); + xbuf = GNUNET_malloc (cbuf_size); + ret = compress (xbuf, + &cbuf_size, + (const Bytef *) cstr, + clen); + GNUNET_assert (Z_OK == ret); + free (cstr); + hdr = GNUNET_malloc (sizeof (*hdr) + cbuf_size); + hdr->ctype = htonl (TALER_EXCHANGE_CONTRACT_PAYMENT_REQUEST); + hdr->clen = htonl ((uint32_t) clen); + memcpy (&hdr[1], + xbuf, + cbuf_size); + GNUNET_free (xbuf); + GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, + &nonce, + sizeof (nonce)); + contract_encrypt (&nonce, + &key, + sizeof (key), + hdr, + sizeof (*hdr) + cbuf_size, + DEPOSIT_SALT, + &xecontract, + &xecontract_size); + GNUNET_free (hdr); + /* prepend purse_pub */ + *econtract = GNUNET_malloc (xecontract_size + sizeof (*purse_pub)); + memcpy (*econtract, + purse_pub, + sizeof (*purse_pub)); + memcpy (sizeof (*purse_pub) + *econtract, + xecontract, + xecontract_size); + *econtract_size = xecontract_size + sizeof (*purse_pub); + GNUNET_free (xecontract); +} + + +json_t * +TALER_CRYPTO_contract_decrypt_for_deposit ( + const struct TALER_ContractDiffiePrivateP *contract_priv, + const void *econtract, + size_t econtract_size) +{ + const struct TALER_PurseContractPublicKeyP *purse_pub = econtract; + + if (econtract_size < sizeof (*purse_pub)) + { + GNUNET_break_op (0); + return NULL; + } + struct GNUNET_HashCode key; + void *xhdr; + size_t hdr_size; + const struct ContractHeaderP *hdr; + char *cstr; + uLongf clen; + json_error_t json_error; + json_t *ret; + + if (GNUNET_OK != + GNUNET_CRYPTO_ecdh_eddsa (&contract_priv->ecdhe_priv, + &purse_pub->eddsa_pub, + &key)) + { + GNUNET_break (0); + return NULL; + } + econtract += sizeof (*purse_pub); + econtract_size -= sizeof (*purse_pub); + if (GNUNET_OK != + contract_decrypt (&key, + sizeof (key), + econtract, + econtract_size, + DEPOSIT_SALT, + &xhdr, + &hdr_size)) + { + GNUNET_break_op (0); + return NULL; + } + if (hdr_size < sizeof (*hdr)) + { + GNUNET_break_op (0); + GNUNET_free (xhdr); + return NULL; + } + hdr = xhdr; + if (TALER_EXCHANGE_CONTRACT_PAYMENT_REQUEST != ntohl (hdr->ctype)) + { + GNUNET_break_op (0); + GNUNET_free (xhdr); + return NULL; + } clen = ntohl (hdr->clen); if (clen >= GNUNET_MAX_MALLOC_CHECKED) { @@ -340,7 +524,6 @@ TALER_CRYPTO_contract_decrypt_for_merge ( GNUNET_free (xhdr); return NULL; } - *merge_priv = hdr->keys.merge_priv; GNUNET_free (xhdr); ret = json_loadb ((char *) cstr, clen, |